“This figure shows concentrations of carbon dioxide in the atmosphere from hundreds of thousands of years ago through 2013, measured in parts per million (ppm). The data come from a variety of historical ice core studies and recent air monitoring sites around the world. Each line represents a different data source.” - United States Environmental Protection Agency
This figure depicts a positive trend in the global atmospheric concentration of carbon dioxide for several thousand years. Carbon dioxide levels have spiked severely since 1950 and are rising at an increasingly rapid rate today.